Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, ban hanh, van anh
nuoc van » nuoc va, nuoc san, luoc van
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
te sach » toc sach
cua cau » cua cac, cua chu, cua cay
hieu ve » hieu va
cho hoc » co hoc, khoa hoc
ty nang » ky nang, ty hang, ly nang
vi cua » vai cua, di cua

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ((ty nang) or (ty xang)) cho hoc. ((hieu ve) OR (hieu van)) cac nuoc van hanh vi cua cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((ty nang) OR (ty xang)) cho hoc. ((hieu ve) OR (hieu van)) cac nuoc van hanh vi cua cau*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ((ty nang) or (ty xang)) cho hoc. ((hieu ve) OR (hieu van)) cac nuoc van hanh vi cua cau*".